This invention relates to improvements in surveillance and intruder detection systems, and in particular the invention relates to systems in which the quality of ambient lighting and the quality and existence of video signals of the surveillance system and of the surveillance field of view are monitored so as to provide appropriate signals when light degradation and/or loss of video is detected, or if the surveillance system itself fails.
The invention addresses the problem of adequately and efficiently monitoring lighting conditions at private and public places which lighting is typically provided for safety reasons. For example, automatic teller machines are commonly accessible for use by bank customers during both daytime and nighttime hours. Drive up locations and parking lots may be provided by businesses for their employees and customers for use both during daytime and nighttime hours. For safety reasons, these areas are lighted, and video equipment, such as cameras, are commonly provided to monitor and record assault or vandalism activities that may occur at such locations. One of the main shortcomings of video surveillance systems is the inability to detect loss of lighting of the area being monitored due to failure of the lighting fixtures or due to vandalism. Another failure can be caused by the loss of camera or video equipment power, video equipment damage, or loss of cable connections due to vandalism or storm damage, which will render the surveillance system inoperative. Also, in order to avoid identification, vandals may cover the surveillance cameras with objects or spray paint the lenses of the cameras. In any such event, the surveillance system is rendered ineffective. There is therefore a need for improvements to such systems by providing a way to detect when lighting conditions deteriorate and when the system becomes inoperative or tampered with by vandals.
The method and apparatus of the invention provides a way of constantly monitoring ambient lighting conditions using currently installed or new CCTV cameras, as well as detecting any loss of video caused by vandals covering or spray painting lenses, the loss of camera power, or the loss of camera cable connections. Existing levels of light at selected points within the monitored area are programmed into the system, and when the light level at any point falls below the programmed level, a failure is detected. In the event of any such failure, the system of the invention produces an alarm signal to notify an existing alarm station. The system of the invention also includes a black level detection system used to notify an alarm station in the event a video camera is blacked out by a vandal or due to other causes. The system of the invention uses the existing video equipment to provide a more efficient and economical way to detect the above-described problems. The present invention may also be incorporated into new equipment as an after market component, or as an integral part of a new surveillance system.